I have a thorn housewarmer back boiler with fire front, I have an open vented type setup however I have 2 pumps in my system , one close to back boiler and comes on when heating is called for , and the other pump is close to the hot water indirect storage tank upstairs in the cupboard

I have a mechanical selector device , i can selct hot water only or hot water and heating together , but not heating only.

I donot seem to have a diverter vavle installed , I have searched for one but I really dont think there is one,

So is it possible to have the above operate without some sort of diverting valve?

cbrpaul,
Many conventional systems are like yours, when the programmer is set to HW it turns on the boiler, when the programmer is set to HW and CH it turns on the boiler and the CH pump. This will operate fine provided you do not want to have CH only. The pump in the cupboard is probably for circulating hot water around your house so that there is minimal delay between turning on the hot tap and getting hot water.
end

[quote="stoneyboy"]cbrpaul,
Many conventional systems are like yours, when the programmer is set to HW it turns on the boiler, when the programmer is set to HW and CH it turns on the boiler and the CH pump. This will operate fine provided you do not want to have CH only. The pump in the cupboard is probably for circulating hot water around your house so that there is minimal delay between turning on the hot tap and getting hot water.
end[/quote]

Thankyou for your reply stoneyboy

So everytime i turn a hot tap on i will get the HW pump come on also , what would trigger this ? its a standard danfoss pump , not any special flow sensing pump that come on automatically. Im not sure the HW pump does this , i will check later when i am home, but i think it pumps hot water from the back boiler around the indirect storage tank

cbrpaul,
Without seeing the system it is difficult to confirm the function of the pump next to your HW cylinder, If it is a circulating pump it will only circulate the water around the hot water piping and will be on when the HW is on.
end

If you type the key words of your question into our search box to the left of the site you may find the answer is already posted or is in the DIY projects section of the website. Every post goes through a monitoring process and using the search box may speed up your answer.